只读行而不是 python 2.7 中的全部内容答案

【问题标题】：Read only lines and not the entire thing in python 2.7只读行而不是 python 2.7 中的全部内容
【发布时间】：2018-02-10 16:33:39
【问题描述】：

如何在下面的代码中注册用户名和密码时，它会在 txt 文件中添加一个新行，当你登录时，它会单独检查 txt 文件中的每一行如果任何一行与登录名匹配，则声明它是正确的，而不是检查用户名和密码是否与整个内容匹配

print "Welcome to UserName and Password Test"
option = raw_input("Would you like to login or register L for Login R for 
register: ")
if option == "R":
    print "Warning Only 1 user can be registered"
    usernamer = raw_input("Desired Username: ")
    passwordr = raw_input("Desired Password: ")
    file = open("Username.txt","w")
    file.write(usernamer + '\n')
    file.close()
    file = open("Password.txt","w")
    file.write(passwordr + '\n')
    file.close
    print "Registered"
else:
    usr = raw_input("Username: ")
    pss = raw_input("Password: ")
    file = open("Username.txt","r")
    if usr == file.read():
        print "Username correct"
        file.close()
    else:
            print "Username incorrect or not registered"
            file.close()
    file = open("Password.txt","r")
    if pss == file.read():
        print "Password correct"
        file.close()
    else:
            print "Password incorrect or not registered"
            file.close()

【问题讨论】：

以附加模式打开（使用'a'而不是'w'）将添加到文件的末尾。使用file.readlines() 获取文件中的行列表，然后使用循环检查每一行是否匹配。

标签： python python-2.7

【解决方案1】：

以下是如何查找文件的某行中是否存在字符串：

contain = False # Indicator of whether some line of a file contains the string
with open(FILENAME, 'r') as file: # Use `with` statement to automatically close file object
    for line in file:
        if string in line:
            contain = True
            break

【讨论】：

【解决方案2】：

我已修改您的代码以使用密码检查逻辑验证密码和用户名。这应该可以。

print "Welcome to UserName and Password Test"
option = raw_input("Would you like to login or register L for Login R for register: ")
if option == "R":
    print "Warning Only 1 user can be registered"
    usernamer = raw_input("Desired Username: ")
    passwordr = raw_input("Desired Password: ")
    file = open("Username.txt","a")
    file.write(usernamer + '\n')
    file.close()
    file = open("Password.txt","a")
    file.write(passwordr + '\n')
    file.close
    print "Registered"
else:
    usr = raw_input("Username: ")
    pss = raw_input("Password: ")
    file = open("Username.txt","r")
    count = 0
    userfound = False
    try:
        for user in file.readlines():
            count += 1
            if usr == user.strip():
                userfound = True
        file.close()
        if not userfound:
            raise
        file = open("Password.txt","r")
        passcount = 0
        for passcode in file.readlines():
            passcount += 1
            if count == passcount:
                if pss == passcode.strip():
                    print 'successfully logged in'
                else:
                    print "Password incorrect or not registered"
                break

        file.close()
    except Exception as e:
        print 'User login error !!!'

【讨论】：

【解决方案3】：

如果你只是想检查用户是否在文件内容中，

如果 usr 在 file.read():
做某事

"==" 检查值是否与其相同，"in" 关键字检查子字符串是否在大字符串中。在 file.read() 中会将整个内容作为一个字符串。

【讨论】：